Treatment of silk rags.



RTE il TATES PATENT OFFICE.

GUSTAV KREUTER, OF LUOKENWALDE, GERMANY.

SPECIFICATION forming part of Letters Patent No. 666,648, dated August 28, 190i).

Application filed April 18, 1898. Serial No- 6771942. (No specimens.) f i To all whom it may concern:

Be it known that I, GUsTAv KRE'U'TER, a subject of the Emperor of Germany, and a resident of the city of Luckenwalde, in the Prov= ince of Brandenburg, Kingdom of Prussia, German Empire, have invented certain new and useful Improvements in the Treatment of Silk Rags to Facilitate their Remanufac= ture into Fabrics; and I do hereby declare that the following is a clear, full, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same.

Heretofore the conversion of silk rags into silk waste by means of the devil or openingmachine has been attended by great danger of spontaneous combustion, owing to the generation of electric sparks by the friction of the teeth of the machine with the silk fibers. For this reason it has been customary to throw silk rags away or to destroy same as being commercially worthless.

The object of my invention is, so to speak, to reclaim this material by removing the danger of spontaneous combust-ion--that is to say, to subject the rags to such treatment as will prevent the generation of electric sparks during the tearing up process. The resultis that I obtain a silk waste which can be bleached, woven, spun, or otherwise worked into a fabric, either as pure silk or in combination with another material, and which can be dyed to any color desired. Fabrics produced from silk waste have many advantages over cotton and woolen fabrics. They are lighter, and as silk is a non-conductor they are warmer. They are also softer, have a better appearance, and are more durable than wool or cotton, and are, moreover, cheaper.

The complete treatment consists, essentially, in the following order of operations: The silk rags are first sorted according to their quantity and color, and all seams, knots, and the like are removed from same. The rags are then washed and afterward placed in a bath of a solution of sulfuric acid of from 3 to 4 Baum. This bath is of the same temperature as the atmosphere at the time being, and the rags are allowed to remain in same for from three to four hours time, after which they are taken out and dried. The rags are then placed in a chamber heated up to about 90 centigrade and left for about an hour in same, at the end of which time any vegetable fibers, such as cotton, contained in the rags will have been burned or become carbonized and will after ward fall away as dust. In case there should be any acid left in the rags this is neutralized or rendered inactive by placing the said rags in a soda bath until there is a slight alkaline reaction, when the rags are taken out and dried. The process up to this point is one which has been in use for other materials prior to this invention. The rags are now placed in thin layers and sprayed with a solution formed of finely-powdered black oxid of manganese suspended in water,oleine,and alum until the said rags are thoroughly saturated. The ingredients of this solution are for everyone hundred kilos of rags one-half to two kilos of powdered black oxid of manganese. One-half to two kilos of alum and two to three kilos of oleine are used according to the quality of the rags. The proportion of black oxid of manganese to the quantity of water is less when the rags are loosely woven than when they are thickly woven, the proportion being within the discretion of the operator from 1:1 to 1: 5. Ordi narily the proportion of the black oxid of manganese to the alum is a solution of alum of about 4 Baum to about double the weight of powdered black oxid of manganese. After the rags have been saturated with the abovementioned solution they are smeared with soft soap. This soft soap has a hydroscopic action and transfers this action to the rags, the silk fibers being thus converted into electric conductors, and the alum in solution aids this action considerably. After having been treated as above the rags can be fed into the devil or opening-machine without any danger of spontaneous combustion. The action of the chemical combination is as follows: When the silk fibers have been converted into conductors, the positive electricity developed upon them by the friction of the silk fibers against the teeth of the devil distributes itself equally over all the fibers in the form of a positive static charge. The black oxid of manganese upon which the negative electricity is developed by the friction of the same with the devil-teeth has the effect of neutraliz'ing the positive electricity on the silk, and

thereby preventing such an accumulation as would cause a spark from the fibers to some metallic part of'the machine and thereby possibly setting fire to the material.

Any desired fabric can be spun or woven or otherwise worked from the silk waste, whether for clothing, hats, insulating material, covers, carpets, or the like, and the said fabric can either be of pure silk or mixed with cotton or W001. The mixing can be effected at any stage after the rags are opened.

The silk-waste obtained by the method described can be bleached either before or after being worked into a fabric and can be dyed just the same as Wool or cotton.

Having fully described my invention, what I claim, and desire to secure by Letters Patcut, is r V V In converting silk rags into silk Waste by means of the opening-machine or devil the process of preventing the formation of electric sparks, which consists in treating the silk rags with a solution of oleine, alum and black oxid of manganese powder and smearing same with soft soap essentially as and in the proportions described.

In witness whereof I have hereunto set my hand in presence of two witnesses.

GUSTAV KREUTER. Witnesses:

C. H. DAY, HENRY I-IAsPER. 

